What happened
On August 8, 2000, a Mudry Cap 10 B, registration F-GIZL, was conducting an aerobatic instruction flight near Ajaccio Aerodrome. The flight was the third aerobatic session for the student pilot, accompanied by an instructor.
While operating at 4,000 feet, the aircraft was performing various maneuvers, including 45-degree climbs and descents on its belly. The instructor directed the student to perform similar maneuvers in an inverted position. During a 45-degree inverted descent, the instructor instructed the student to transition to level inverted flight. Instead of pushing the control stick forward to reduce the pitch, the student pulled back on the stick.
This incorrect input caused the aircraft to deviate from the intended flight path. The instructor took control of the aircraft but noted that the controls felt extremely heavy. During this period of instability, the student reacted by shouting that they were "letting go of everything."
To recover, the instructor leveled the aircraft in horizontal flight while monitoring the accelerometer. Once the airspeed had decreased, the instructor performed a positive-g half-roll. During these maneuvers, the aircraft exceeded its VNE (never-exceed speed) of 340 km/h, though load factors remained within the permitted limits of +3g and -3g. The excursion resulted in cracking of the windshield.
The investigation
Investigators examined the flight sequence and the mechanical state of the aircraft's controls. Post-flight inspections and pre-flight checks were conducted to determine if any mechanical interference or a "hard point" in the flight controls contributed to the difficulty experienced by the instructor. No mechanical defects or obstructions in the control linkages were identified.